Hmm. I have a somewhat different perspective. My overall message is that if you think your son is ready for algebra and he's getting high scores on PRE-tests, you should seriously consider putting him in algebra.
Here's why.
Personally, I'm not convinced about the need for pre-algebra with gifted kids. My son is taking pre-algebra and I've looked through his textbook. It adheres to California standards and so is a fair description of pre-algebra in this entire populous state.
Roughly a third of the book reviews late elementary-level math (fractions, decimals) and does some middle school math. The rest of the book deals mostly with basic non-rigorous algebra, with a chapter on triangles.
So anyone who does this course will end up repeating ~2/3 of it during algebra 1, with slightly harder problems.
This is why I think pre-algebra isn't a good choice for gifties.Way back when I was in school, pre-algebra was mainly aimed at students who weren't super-strong in math. It made sense: they got a review of important stuff from late elementary (5th/6th then) and junior high. Then they went through some basic algebra slowly. This approach helped them build a foundation for algebra 1 and beyond. Alternatively, the stronger students took algebra in 9th grade and the gifties took it in 8th (because 8th grade math was a mostly a basic version of pre-algebra).
These days, schools seem to have forgotten all this stuff and push pre-algebra on 7th graders in an effort to get everyone into algebra at an age that used to be the target for gifted students.
The weaker students miss out on a lot of extra practice that they need. The gifties presumably get bored in algebra 1 until they hit the new stuff sometime in January or so.
So while people have made good points about not wanting to miss important concepts, it's highly likely that your son WON'T miss them if he takes algebra 1, because
it just repeats pre-algebra anyway. Ergo, my advice is to look through his current textbook carefully and compare it to the school's algebra 1 textbook. You may find a lot of repeated topics. After you've looked at both books, you'll be able to make an informed decision about which course to put him in.
